Ailanthus altissima – Biology and Ecology

Research Issue

Ailanthus altissima (tree of heaven) is a shade-intolerant, fast-growing, nonnative tree that invades many plant community types, including forests, nationwide.  While shade-intolerant, A. altissima can survive as a slow-growing seedling or sprout until light conditions improve.  Developing a better understanding of the environmental conditions in which this species is likely to become established and spread is critical for successful forest management that prevents or alleviates forest invasions.  These conditions also include estimating this species’ competitive ability with associated native species in forests of variable quality and successional stages, which will lead to more successful restoration projects.  

 Our Research

We began our research on A. altissima by first focusing on its competitive ability with associated native species, including Rhus typhina (staghorn sumac; possible roadside replacement species) and Acer rubrum (red maple; possible forest replacement species).  In both cases, preliminary results show that A. altissima may not be more competitive than these native species under optimal environmental conditions, if the native species arrive first or at the same time as A. altissima.  We will be repeating our studies at a larger scale and including additional environmental conditions, such as the addition of mycorrhizae, different light levels, and different timing scenarios. Preliminary results of a small study show that the addition of mycorrizae improves A. altissima’s competitive ability over A. rubrum.  We are also evaluating A. altissima’s reproductive strategies (sexual and asexual).  The latter includes estimating the likelihood of sprout formation under different environmental conditions.  (While we have shown that new shoots can arise from root segments as short as 1 cm, we would like to know if vegetative reproduction  precludes sexual reproduction or vice versa under different conditions).  We also would like to confirm that dioecy is the dominant mode of sexual reproduction; preliminary evidence of hermaphrodites and seed production of bagged female flowers, suggests a more complex strategy.   Finally, with the help of a cooperator, we are evaluating the genetic make-up of the two sexes as well as A. altissima’s population genetics.    

Expected Outcomes

 We expect to define a set of environmental conditions that place native species at an advantage over A. altissima.  Some of these less than optimal conditions for A. altissima may include being able to manipulate factors that control sexual vs. asexual reproduction.

Aldrich, P.R., J. Briguglio, S. Kapadia, M. Morker, A. Raval, P. Kalra, C.D. Huebner, and G. Greer. In press. Genetic Structure of the Invasive Tree Ailanthus altissima in Eastern U.S. Cities. Journal of Botany. 

Research Results

Aldrich, P.R.; Brusa, A.; Heinz, C.A.; Greer, G.K.; Huebner, C.D. . Floral visitation of the invasive stinking ash in Western suburban Chicago. Transactions of the Illinois State Academy of Science 101 (1&2): 1-12.

Huebner, C. D., C. McQuattie, and J. Rebbeck.  2007. Mycorrhizal associations in Ailanthus altissima (Simaroubaceae) from forested and non-forested sites.  Journal of the Torrey Botanical Society 134(1):  27-33.

Research Participants

Principal Investigator

• Cynthia D. Huebner, Research Botanist/Ecologist, U.S. Forest Service, Northern Research Station

Research Partners

• Preston Aldrich, Benedictine University, Lisle, IL
• Gary Greer, Grand Valley State University, Allendale, MI
• Jim McGraw, West Virginia University, WV

For further details log on website :
https://www.nrs.fs.fed.us/disturbance/invasive_species/ailanthus_altissima_biology/